He said they are not incompatible by design.He didn't.
He said that FBI, CFW and all the pirating tools are incompatible by design.
But he also said that Ninjhax 2.0/TubeHax/IronHax didn't have disadvantages compared to Ninjhax.
https://twitter.com/smealum/status/633856803944574976 (this tweet and another one higher on the page.)
You're half right. Yellows8 likely does have kernel exploits, but until someone else finds them, they remain unreleased.atI think Thay yellows have a kernel exploit but he will get it secret until a firmware that fix the hombrew chanel